Underfloor heating and then Tiling on top

[toerag]

Underfloor heating wet and tiling: We have builders in and I am very concerned. We have built an extension to the back of the house consisting of a cellar and a garden room. The garden room has underfloor heating between the joists. The pipes were clipped to insulation ~(?name is celotex or something) and dryish sand cement mixture was spread over this and then a few days later a self levelling product was poured over. The heating was put on Thursday. Today there are cracks - some hairline and some thicker than hairline. We have the tiles here as we were asked. My question: Are these cracks normal? Should I be concerned - is it indicative of something wrong? What is the order of work for laying the tiles in this room? We have had lots of problems on this build because of the site - we live in a hill - and the weather. I am now very anxious about everything and would like to be reassured about what is happenning.

Thank you for reading this and even more grateful if anyone can answer the queries and reassure me.

Kind regards

:gettree:

 

[grumpygrouter]

It sounds to me like the sand/cement screed has not been left long enough to dry/cure properly. it should have been left for 1 day/mm of thickness unless a rapid setting mixture had been used. When the heating was switched on, it should have been done at a very low setting first of all and then increased by about 5deg C per day until max operating temp was reached. You may have heated your "not quite ready" screed too quickly which has caused the cracking. I think some fine cracking may be expected as part of the settling process but large cracks may be cause for concern.

Do you have any pics to show us your problem?

 

[Sully]

and dryish sand cement mixture was spread over this and then a few days later a self levelling product was poured over. The heating was put on Thursday.

I'm with Grumpy on this - doesn't sound good. Just to clarify, heating was turned on on Thursday. What was the timescale between the pipe / sand & cement / levelling compound installation and last Thursday? Secondly, was the heating just turned on or increased in temp slowly as Grump says?

 

[toerag]

Hi

Thanks for your very prompt reply. I have taken photographs but the site won't let me attach them - says it is invalid.

Really worried in case this is a problem as we have had so many. What should happen next? Can you tell me the correct course of action that should be taken?

Kind regards

Toerag

 

[DHTiling]

To get your pics to load..you might have to resize them...the limit is 600x400

 

[toerag]

All the days are a blur! I would say the screed and levelling has been done at least over a week. As far as I know the heating has not been adjusted - just put on but it is just warm too touch and there is a cold cellar underneath. The floor has been reinforced with thick plywood - ? 1/2" thick.

Thank you for your quick reply.

Kind regards

Hester

 

[toerag]

I will need to wait till my other half comes back from his mum's as that is his department - bit beyond me I'm afraid.
There isn't an attachment button on the toolbar now. Where will I find that?

Thank you

Toerag

 

[DHTiling]

Hit this button>>>> and the attachment manager is there if you scroll down...or you could create an album in your profile and load pics into that...

Some cracks can appear in new screeds this is down to curling of the screed, but maybe made worse by turning the heating on full whack....this would have shocked the screed....if it hasn't loosened any area's then you can use an uncoupling/crack isolation membrane this will prevent the cracks transfering to the tiled installation..and allows the substrate to expand and contract without effecting the tiles....

Click HERE for info......

 

[toerag]

Hi

I had difficulty logging on earlier and I thought I had been successful in sending this already.

I have attached a photograph which is 30% of its original size. i have several more I can send if it would be helpful.

Any help is appreciated. Really want to know if this is a problem. If it is do I direct the builder to the site Mr Grumpy asked me to look at. If it's a 'normal' problem what should I expect to be done.

Kind regards

Toerag

 

[toerag]

Update:

The builder who was here today has said the top layer - the levelling layer - is to be taken off as it wasn't applied properly. does this solve the problem? What should I watch out for? When should the tiler start?

Thank you for reading this and the supportive replies I have had.
Apologies are due to Dave for calling him Grumpy - in my defence I am totally stressed out.

Kind regards


Toerag :santa_cheesy: